ref: 8f1eb1ac77640d9cd189c49fe48af8cde65eceb1
dir: /sys/src/cmd/hgfs/revlog.c/
#include <u.h> #include <libc.h> #include <thread.h> #include "dat.h" #include "fns.h" int fmktemp(void) { static ulong id = 1; char path[MAXPATH]; snprint(path, sizeof(path), "/tmp/hg%.12d%.8lux", getpid(), id++); return create(path, OEXCL|ORDWR|ORCLOSE, 0600); } void revlogupdate(Revlog *r) { uchar buf[64]; Revmap *m; vlong noff; int rev; if(seek(r->ifd, r->ioff, 0) < 0) return; for(rev=r->nmap;;rev++){ if(readn(r->ifd, buf, sizeof(buf)) != sizeof(buf)) break; if((rev % 16) == 0) r->map = realloc(r->map, sizeof(r->map[0])*(rev+16)); m = &r->map[rev]; memset(m, 0, sizeof(*m)); m->hoff = (vlong)buf[0]<<40 | (vlong)buf[1]<<32 | (vlong)buf[2]<<24 | (vlong)buf[3]<<16 | (vlong)buf[4]<<8 | (vlong)buf[5]; if(rev == 0) m->hoff &= 0xFFFF; m->rev = rev; m->flags = buf[6]<<8 | buf[7]; m->hlen = buf[8]<<24 | buf[9]<<16 | buf[10]<<8 | buf[11]; m->flen = buf[12]<<24 | buf[13]<<16 | buf[14]<<8 | buf[15]; m->baserev = buf[16]<<24 | buf[17]<<16 | buf[18]<<8 | buf[19]; m->linkrev = buf[20]<<24 | buf[21]<<16 | buf[22]<<8 | buf[23]; m->p1rev = buf[24]<<24 | buf[25]<<16 | buf[26]<<8 | buf[27]; m->p2rev = buf[28]<<24 | buf[29]<<16 | buf[30]<<8 | buf[31]; memmove(m->hash, buf+32, HASHSZ); noff = r->ioff + sizeof(buf); if(r->dfd < 0){ m->hoff = noff; noff = seek(r->ifd, m->hoff + m->hlen, 0); if(noff < 0) break; } r->ioff = noff; } r->nmap = rev; } int revlogopen(Revlog *r, char *path, int mode) { r->ifd = -1; r->dfd = -1; r->tfd = -1; r->tid = -1; path = smprint("%s.i", path); if((r->ifd = open(path, mode)) < 0){ free(path); return -1; } path[strlen(path)-1] = 'd'; r->dfd = open(path, mode); path[strlen(path)-2] = 0; r->path = path; r->ioff = 0; r->nmap = 0; r->map = nil; revlogupdate(r); return 0; } void revlogclose(Revlog *r) { if(r->ifd >= 0){ close(r->ifd); r->ifd = -1; } if(r->dfd >= 0){ close(r->dfd); r->dfd = -1; } if(r->tfd >= 0){ close(r->tfd); r->tfd = -1; } r->tid = -1; free(r->map); r->map = nil; r->nmap = 0; free(r->path); r->path = nil; } uchar* revhash(Revlog *r, int rev) { if(rev < 0 || rev >= r->nmap) return nullid; return r->map[rev].hash; } int hashrev(Revlog *r, uchar hash[]) { int rev; for(rev=0; rev<r->nmap; rev++) if(memcmp(r->map[rev].hash, hash, HASHSZ) == 0) return rev; return -1; } static int prevlogrev(Revlog *r, int rev) { if(r->map[rev].baserev == rev) return -1; return rev-1; } static int prevbundlerev(Revlog *r, int rev) { if(r->map[rev].baserev == rev) return -1; return r->map[rev].p1rev; } static Revmap** getchain1(Revlog *r, int rev, int *count, int (*next)(Revlog *, int)) { Revmap **chain; if(rev < 0 || rev >= r->nmap){ if(*count <= 0) return nil; chain = malloc(sizeof(chain[0]) * ((*count)+1)); chain[*count] = nil; *count = 0; }else{ (*count)++; if(chain = getchain1(r, (*next)(r, rev), count, next)) chain[(*count)++] = &r->map[rev]; } return chain; } static Revmap** getchain(Revlog *r, int rev, int (*next)(Revlog *, int)) { int count = 0; return getchain1(r, rev, &count, next); } int revlogextract(Revlog *r, int rev, int ofd) { int err, hfd, pfd, bfd; uchar hash[HASHSZ]; Revmap **chain, *m; char buf[32]; vlong off; int i; err = -1; bfd = -1; pfd = -1; if((chain = getchain(r, rev, prevlogrev)) == nil){ werrstr("bad patch chain"); goto errout; } off = seek(ofd, 0, 1); if(off < 0){ werrstr("seek outfile: %r"); goto errout; } hfd = r->dfd < 0 ? r->ifd : r->dfd; for(i=0; m = chain[i]; i++){ if(seek(hfd, m->hoff, 0) < 0){ werrstr("seek index: %r"); goto errout; } if(m == chain[0] && m->baserev == m->rev){ if(chain[1]){ if(bfd >= 0 && bfd != ofd) close(bfd); if((bfd = fmktemp()) < 0){ werrstr("create basefile: %r"); goto errout; } } else bfd = ofd; if(funzip(bfd, hfd, m->hlen) < 0){ werrstr("unzip basefile: %r"); goto errout; } } else { if(pfd < 0){ if((pfd = fmktemp()) < 0){ werrstr("create patchfile: %r"); goto errout; } } /* put a mark before the patch data */ snprint(buf, sizeof(buf), "%H", m->hash); if(fpatchmark(pfd, buf) < 0){ werrstr("patchmark: %r"); goto errout; } if(funzip(pfd, hfd, m->hlen) < 0){ werrstr("unzip patchfile: %r"); goto errout; } } } m = chain[i-1]; if(pfd >= 0 && bfd >= 0 && bfd != ofd){ if(seek(pfd, 0, 0) < 0){ werrstr("seek patchfile: %r"); goto errout; } if(fpatch(ofd, bfd, pfd) < 0){ werrstr("patch: %r"); goto errout; } } if(seek(ofd, off, 0) < 0){ werrstr("seek outfile: %r"); goto errout; } if(fhash(ofd, revhash(r, m->p1rev), revhash(r, m->p2rev), hash) < 0){ werrstr("hash outfile: %r"); goto errout; } if(memcmp(m->hash, hash, HASHSZ)){ werrstr("got bad hash"); goto errout; } err = 0; errout: if(pfd >= 0) close(pfd); if(bfd >= 0 && bfd != ofd) close(bfd); free(chain); return err; } int revlogopentemp(Revlog *r, int rev) { int fd; if(r->tfd < 0 || rev != r->tid){ if((fd = fmktemp()) < 0) return -1; if(revlogextract(r, rev, fd) < 0){ close(fd); return -1; } if(r->tfd >= 0) close(r->tfd); r->tfd = fd; r->tid = rev; } fd = dup(r->tfd, -1); if(seek(fd, 0, 0) < 0){ close(fd); return -1; } return fd; } int fmetaheader(int fd) { static char magic[2] = { 0x01, 0x0A, }; char buf[4096], *s, *p; int o, n; o = 0; while(o < sizeof(buf)){ if((n = pread(fd, buf+o, sizeof(buf)-o, o)) <= 0) break; o += n; if(o < sizeof(magic)) continue; if(memcmp(buf, magic, sizeof(magic)) != 0) break; s = buf + sizeof(magic); while((s - buf) <= (o - sizeof(magic))){ if((p = memchr(s, magic[0], o - (s - buf))) == nil) break; if(memcmp(p, magic, sizeof(magic)) == 0) return (p - buf) + sizeof(magic); s = p+1; } } return 0; }